Selected 3-trichloromethyl-5-substituted 1,2,4-thiadiazoles

ABSTRACT

Selected 3-trichloromethyl-5-substituted-1,2,4-thiadiazoles having the formula   WHEREIN R is m-haloanilino or N,N-di(lower alkyl) dithiocarbamoyl are prepared by reacting 3-trichloromethyl-5chloro-1,2,4-thiadiazole with the appropriate active hydrogencontaining compound, or a metal salt thereof. These compounds are valuable biocides.

United Stat Smith SELECTED 3-TRICHLOROMETHYL-S-SUBSTITUTED 1,2,4-THIADIAZOLES Eric Smith, PO. Box 208, Farmington, Conn. 06032 Oct. 29, 1973 (Under Rule 47) Appl. No.: 410,728

Related US. Application Data Continuation-in-part of Ser. No. 98,182, Dec. 14, I970, abandoned, which is a division of Ser. No. 751,728, Aug. 12, 1968, Pat. No. 3,573,3l7.

Inventor:

Filed:

US. Cl 260/302 SD; 106/15; 260/45.8 SN;

260/3068 D; 424/270 Int. Cl C07d 91/60 Field of Search 260/3068 D, 302 SD References Cited UNITED STATES PATENTS 7/1966 Schroedor 260/3068 D [451 May 20, 1975 3,324,141 6/1967 Bernstein 260/3068 D Primary ExaminerRichard J. Gallagher Attorney, Agent, or FirmRobert L. Andersen [57] ABSTRACT Selected 3-trichloromethyl-5-substitutedl ,2,4- thiadiazoles having the formula l i R el e- 3 Claims, No Drawings 1 SELECTED 3-TRICHLOROMETHYL-S-SUBSTITUTED 1 ,2,4-THIADIAZOLES This application is a continuation-in-part of copending application Ser. No. 98,182, filed Dec. 14, 1970, now abandoned, which was a divisional of Ser. No. 751,728, filed Aug. 12, 1968, now US. Pat. No. 3,573,317.

This invention relates to selectively substituted thiadiazoles having improved biocidal properties. More particularly, this invention relates to 3-trichloromethyl- 5-substituted-l,2,4-thiadiazoles having the formula wherein R is m-haloanilino or N,N-di(lower alkyl)- dithiocarbamoyl.

Various 3-trichloromethyl-5-substituted-l ,2,4- thiadiazoles have been previously prepared and reported in the literature. For example US. Pat. -No. 3,260,725 discloses certain substituted thiadiazoles which are useful as soil fungicides.

Now it has been found in accordance with this invention that selectively substituted thiadiazoles having the formula I can be prepared which have improved biocidal properties.

The compounds I of this invention are prepared by reacting 3-trichloromethyl-5-chlorol ,2,4-thiadiazole with selected active-hydrogen containing compounds, or metal salts thereof, in accordance with the following general equation wherein R is as previously described and M is an inorganic cation such as an alkali or alkaline earth metal.

Illustrative compounds which can be employed in the preparation of the substituted thiadiazoles of this invention are those having the formula [I wherein R is mhaloanilino or N,N-di(lower alkyl) dithiocarbamoyl.

Representative compounds II include such as mhaloanilines such as m-chloroaniline, m-bromoaniline and m-fluoroaniline and di(lower alkyl)- dithiocarbamates such as sodium diethyldithiocarbamate and sodium dibutyldithiocarbamate wherein the N-substituted di alkyl moieties each have 14 carbon atoms. Particularly preferred in the preparation of the thiadiazoles of this invention are compounds II where R is m-chloroanilino or N,N-diethyldithiocarbamoyl.

The 3-trichloromethyl-5-substituted-1 ,2,4- thiadiazoles l of this invention are readily prepared by reacting 3-trichloromethyl-5-chloro-l ,2,4-thiadiazole with the appropriate co-reactant II at a temperature between about 0 and about 150C., and preferably at a temperature between about 30C. and about C.

While the reaction will proceed in the absence of a solvent, it is preferred to employ solvents or inert dilutes in the preparation of the thiadiazoles 1. Suitable solvents include acetone, water, methylethyl ketone, xylene, ethyl ether, chloroform, carbon tetrachloride and chlorobenzene.

Where a basic compound having the formula RH is employed as co-reactant ll, an excess of the compound may be employed to pick up the hydrogen chloride evolved in the reaction. If a compound having the formula RH that is not strongly basic is employed, acid acceptors such as triethylamine, tributylamine, pyridine, dimethylaniline and the like can be used.

The 3-trichloromethyl-5-substituted-1,2,4- thiadiazoles l are obtained in high yield and excellent purity, and are readily isolated by conventional techniques such as filtration, distillation, recrystallization, and the like.

As previously mentioned, the 3-trichloromethyl-5- substituted-l,2,4-thiadiazoles l of this invention are valuable biocides. The efficiency of the compounds of this invention for this application was particularly surprising and unexpected since it was found that 3- trichloromethyl-S-ethoxy-l,2,4-thiadiazole was ineffective in certain applications where the compounds of this invention exhibited strong biocidal properties. For example, 3-trichloromethyl-5-(m-chloroanilino l ,2,4- thiadiazole was effective against selected bacteria, all but one fungus and all algae tested at concentrations far below the minimum inhibitory level of 3-trichloromethyl-S-ethoxy 1,2,4-thiadiazole. Likewise, 3- trichloromethyl-S-(N,N-diethyldithiocarbamoyl)- l,2,4-thiadiazole substantially greater activity against all bacteria and most algae than did 3-trichloromethyl- 5-ethoxy-l,2,4-thiadiazole. The improved biocidal activity of the compounds I over 3-trichloromethyl-5- ethoxy-l,2,4-thiadiazole is illustrated by the following results of comparative in vitro studies.

ORGANISM MINIMUM INHlBITORY CONCENTRATION (microgram/ml) for: BACTERIA A* B** C*** ,S'. aureus 1,250 5 1,250 S. lutea 625 2.5 2,500 S. faecalis 1,250 625 20 B. cereus 625 5 l E. Coli L250 625 2,500 S. typhinmurium 1,250 625 2,500 Ps. aeruginosa 1,250 625 2,500 P. vulgaris 625 2.5 5

FUNGI A. niger 1,250 313 P. pullularia 1,250 156 P. vermiculatum 1,250 10 C. resiniae 1,250 1,250 T. mentagrophytes 625 1 F. semitectum 1,250 20 C. albicans 1,250 10 S. cerevisiae 625 l0 ALGAE C. pyrenoidosa 156 313 l S. obliguus 156 5 l P. fareolarum 156 39 l O. bometi 5 39 l 78 20 l Zygnema -Continued ORGANISM MINIMUM INHIBITORY CONCENTRATION (microgram/ml) for: BACTERIA A* B** r C*** Diatoms 156 313 39 3 -trichloromcthyI-5 -ethoxy l ,2 ,4-lhiadiuzolv: 3 -trichloromcthyl-5-(N,N-diethyldithiocnrbnmoyl)-1.2 .4-thiudinzolc 3-trichloromethyl-S-m-chlorounilino 1,2.4-thiudiazolc Thus, the thiadiazoles I of this invention can be employed as biocides for paints, plastics, cements, and the like.

The following examples will serve to illustrate the preparation of various 3-trichloromethyl-5-substituted- 1,2,4-thiadiazoles in accordance with the practice of this invention.

EXAMPLE I 3-Trichloromethyl-5-chloro-1,2,4-thiadiazole (23.80 g.) and m-chloroaniline (25.52 g.) were refluxed in 50 ml. of xylene for 2% hours. After cooling to room temperature, the reaction mixute was filtered and the filtrate evaporated to remove xylene. The resulting solid product was slurried with dilute hydrochloric acid, filtered, dried and recrystallized from cyclohexane to provide a product having a melting point of 149.5152C. The following analytical data revealed that 3-trichloromethyl-5-(m-chloroanilino)-l ,2,4- thiadiazole had been obtained.

Anal. Calcd. for C I'I,,Cl N S: C, 32.82; H, 1.53; CI, 43.06;

- N, 12.76 Found: C, 331.2; H, 1.69; CI, 42.8;

EXAMPLE II 3-Trichloromethyl-S-chloro-1,2,4-thiadiazole (23.80

Anal. Calcd. for C H CI N S C, 27.39; H, 2.87;

CI, 30.331N, 11.98;

Found: C, 27.56, H, 2.95;

CI, 30.7 ;N, 12.32;

What is claimed is: l. A 3-trichloromethyl-5-substituted-1,2,4- thiadiazole having the formula wherein R is m-haloanilino or N,N-di(lower alkyl having 1-4 carbons)-dithiocarbamoyl.

2. The compound of claim 1 having the same 3- trichloromethyl-5-(m-chloroanilino)-1,2,4-thiadiazole.

3. The compound of claim 1 having the name 3- trichloromethyl-S-(N ,N-diethyldithiocarbamoyl 1,2,4-thiadiazole.

r TED STATES PATENT OFFICE @EHFEQAT Q Patent No. 3 r 884 I Dat d May 20 1975 Inventofls) Eric Smith It is certified that error appears in the above-=identified patent and that said Letters Patent are hereby corrected as shown below:

Column 3, line 5, "BACTERIA" should read ALGAE-.

Column 4, line 36, "same" should read name-.

int and geaied this fifth ay of August 1975 [SEAL] AIMSI.

RUTH C. MASON C. MARSHALL DANN AlIvsIing Officer (ummissimn'r of lulcnrs uml Trudvmurkx 

1. A 3-TRICHLOROMETHYL-5-SUBSTITUTED-1,2,4-THIADIAZOLE HAVING THE FORMULA
 2. The compound of claim 1 having the same 3-trichloromethyl-5-(m-chloroanilino)-1,2,4-thiadiazole.
 3. The compound of claim 1 having the name 3-trichloromethyl-5-(N,N-diethyldithiocarbamoyl)-1,2,4-thiadiazole. 